Abstract [en]

Cutaneous melanoma is characterized by poor patient outcome in its later stages. The search for genetic markers is therefore crucial for the identification of populations at risk for melanoma. Highly polymorphic CA repeats in 3 proximity in the MANBA gene were examined by PCR-capillary electrophoresis in 185 Swedish melanoma patients and 441 tumor-free age- and gender-matched individuals. The associations of the polymorphisms with melanoma risk, the pigment phenotypes of the patients and tumor characteristics were analyzed. A significant difference in allelic distribution between melanoma patients and tumor-free individuals was observed. The frequency of the MANBA genotype <21CAs/>= 21CAs was significantly higher in melanoma patients than in the controls. When comparing allele distribution in patients and their matched controls, the allele <21 CAs was found to be associated with the female gender (39.8 vs. 31.2%, P=0.041, OR=1.46, 95% Cl 1.02-2.10), but not with male gender (34.4 vs. 30.9%, P=0.39). Within the melanoma group, there were no differences in the distribution of the MANBA alleles associated with patient gender or age before or after 55 years at diagnosis, nor was there any association between the MANBA genotype and pigment phenotype or tumor sites. The MANBA allele <21CAs was, however, associated with thin melanomas at diagnosis (Breslow thickness <= 1.5 mm and Clark levels I and II). In conclusion, these data suggest that MANBA polymorphisms might be an indicator of tumor growth and progression and, together with other markers, could be used to identify individuals at increased risk of melanoma.

Abstract [en]

The inhibitor of differentiation/DNA binding 1 (Id-1), a negative regulator of basic helix-loop-helix transcription factors, plays an important role in the regulation of cell proliferation and differentiation. We examined the Id-1 expression by immunohistochemistry in 9 adenomas, 79 primary colorectal adenocarcinomas matched with 40 adjacent normal mucosa specimens and its relationship with clinicopathological factors. The Id-1 expression was increased in the carcinoma compared to the adjacent normal mucosa either in the unmatched and matched samples or to the adenoma. There was no significant difference in the Id-1 expression between normal mucosa and adenoma. The Id-1 expression of carcinoma was increased from Dukes' stages A to B, to C and to D. The cases with lymph node metastasis had a higher rate of a stronger Id-1 expression than those without lymph node metastasis. In conclusion, Id-1 overexpression plays an important role in colorectal cancer progression.

Abstract [en]

RAD50/MRE11/NBS1 complex is essential for DNA double-strand break repair and for maintaining genomic integrity. In this study, we immunohisto-chemically examined MRE11, NBS1 and RAD50 expression in primary CRCs (n=208), the corresponding distant (n=41) and adjacent normal mucosa (n=130), and lymph node metastases (n=26), and investigated their clinicopathological significance in colorectal cancers (CRCs). We found that the intensity and percentage of MRE11 and NBS1 in primary CRCs were positively correlated with each other and with RAD50 (P<0.0001). Strong expression of MRE11, NBS1 or combined RAD50/MRE11/NBS1 was related to MSS, positive hMLH1 expression, earlier tumour stage (TNM stage I and II) and favourable survival (P<0.05). A high percentage of MRE11 expression was associated with less local recurrence and high apoptotic activity (P<0.05). In MSS CRCs, the expression of MRE11 and NBS1 was stronger than that in normal mucosa (P<0.05), and strong expression of NBS1 in primary tumour was related to favourable survival of patients in TNM stage I and II (univariate analysis: P=0.03; multivariate analysis: P=0.07). In MSI CRCs, neither MRE11 nor NBS1 expression showed differences among normal mucosa, primary tumour and metastasis, or among clinicopathological variables. In conclusion, RAD50/MRE11/NBS1 proteins interacted with each other, which had different clinicopathlogical significance in MSS and MSI CRCs, and further, each component of the complex might have additional roles. NBS1 might be a prognostic factor for patients with MSS tumour in TNM stage I and II.

Abstract [en]

RAD50 protein is essential for DNA double-strand break repair and maintaining genomic integrity. In this study, we investigated the clinicopathological significance of hRAD50 expression and mutation in microsatellite stable (MSS) and unstable (MSI) colorectal cancers (CRCs). hRAD50 expression was examined in primary CRC (n=268), the corresponding distant (n=69) and adjacent normal mucosa (n=138), and lymph node metastasis (n=44) by immunohistochemistry. hRAD50 mutation was analyzed in 87 primary CRCs by PCR-SSCP-DNA sequencing. hRAD50 expression was increased in MSS primary CRCs, but not MSI ones, compared with distant/adjacent normal mucosa (p<0.05). There was no difference in the hRAD50 expression between primary and metastatic CRCs. The increased hRAD50 expression in MSS primary CRCs was related (p<0.05) or tended to be related (p=0.05) to early tumor stage, better differentiation, high inflammatory infiltration, p53 overexpression. Frameshift mutations of (A)_{9} at coding region of hRAD50 were only found in MSI CRCs. Our results suggest that hRAD50 may play different roles in the development of MSS and MSI CRCs: increased hRAD50 expression in MSS CRCs {may be a cellular response against tumor from further progression}, while hRAD50 mutation may be involved in the development of MSI CRCs.

Open this publication in new window or tab >>The Gln/Gln genotype of XPD codon 751 as a genetic marker for melanoma risk and Lys/Gln as an important predictor for melanoma progression: A case control study in the Swedish population

Abstract [en]

The Xeroderma pigmentosum complementation group D (XPD) is a critical protein in the nucleotide excision repair system for DNA damage. Genetic variations in XPD exert an important effect on the capacity of DNA repair. In this study, we examined Lys751Gln polymorphism at the XPD gene in 244 melanoma patients and 251 healthy individuals (as controls) from the south-eastern region of Sweden. The associations of polymorphism with melanoma risk, as well as with melanoma features and pigment phenotypes of the melanoma patients were analysed. DNA was extracted from the mononuclear cells of venous blood of the melanoma patients and controls. XPD codon 751 was genotyped by the PCR restriction fragment length polymorphism technique. Results showed that there was no difference in the distribution of the XPD codon 751 genotypes between the melanoma patients and healthy controls. However, the Gln/Gln genotype was found to be associated with melanoma risk in the male population. Furthermore, the frequency of the Gln/Gln genotype was significantly higher in the early stages of melanomas, whereas Lys/ Gln was more frequent in the later stages and in the patients with melanoma located on intermittently UV-exposed areas. No correlations between the polymorphisms and phenotypes of the patients were found. In conclusion, Gln/Gln was a useful genetic marker for melanoma risk in the males, while Lys/Gln was an important predictor for melanoma progression.

Abstract [en]

PURPOSE: Human skin melanoma at later stages usually has an extremely poor prognosis. It is of importance to search for biologic markers to identify and monitor individuals at risk for melanoma for early diagnosis and to avoid tumor progression. The FAS gene and its natural ligand (FASL) gene initiate the death signal cascade, playing a central role in the apoptotic signaling pathway and tumor growth and metastasis. PATIENTS AND METHODS: In this study, we analyzed polymorphisms in 229 patients with melanoma and 351 age- and gender-matched tumor-free individuals. Genomic DNAs were isolated from mononuclear cells in peripheral vein blood, and the polymorphisms were examined with polymerase chain reaction-restriction fragment length polymorphism techniques. Frequency in distribution of the polymorphisms was compared between the patients with melanoma and the healthy control subjects, and associations with patients' pigment phenotypes, age at diagnosis, and melanoma characteristics were analyzed. RESULTS AND CONCLUSIONS: The FAS-1377, FAS-670, and FASL-844 polymorphisms were not found to be markers of melanoma risk (P > 0.05). In patients with melanoma, frequencies of the FAS-1377, FAS-670, and FASL-844 polymorphisms were different between the patients aged <50 and > or =50 years (P < or = 0.025, P < or = 0.025, and P < or = 0.01). Moreover, the FAS-670 polymorphism correlated with tumor Breslow thickness (P < or = 0.01) and Clark level (P < or = 0.001) and was associated with tumors developing in sun-exposed locations (P < or = 0.001). FAS and FASL were not markers for melanoma risk but might be important in the development and progression of sun-induced melanoma independently of skin type.

Abstract [en]

In this study, functional polymorphisms of NF-κB1 and NF-κBIα genes were examined in 185 melanoma patients and 438 tumor-free individuals. Associations of the polymorphisms with melanoma risk, age and pigment phenotypes of the patients and clinico-pathological tumor characteristics were analyzed. DNAs were isolated from mononuclear cells of venous blood. Polymorphisms of the genes were genotyped by a PCR-RFLP technique, and transcription level of NF-κBIα was examined by a quantitative real-time reverse transcription PCR. Results showed that both ATTG insertion polymorphism of NF-κB1 and A to G polymorphism of NF-κBIα genes were correlated with melanoma risk, especially, in a combination of ATTG2/ATTGT2 and GG. NF-κB1 ATTG2/ATTG2 and NF-κBIα GG genotypes were associated with male gender and age > 65 years (at diagnosis). Patients with ATTG1/ATTG1 genotype had thinner tumors and lower Clark levels at diagnosis. Frequency of ATTG1/ATTG1 genotype was higher in patients with melanomas on intermittently sun-exposed pattern of the body and NF-κBIα GG was more frequent in the patients with melanomas at rarely exposed sites. There were no differences in the gene transcription level between patients with different NF-κBIα genotypes. These data suggest that NF-κB1 and NF-κBIα genes might be susceptible genes for melanoma risk and functional polymorphisms of these genes might be biological predictors for melanoma progression.

Abstract [en]

Nuclear factor-κB (NF-κB) is responsible for the expression by regulating many genes for immune response, cell adhesion, differentiation, proliferation, angiogenesis and apoptosis. The function of NF-κB is inhibited by binding to NF-κB inhibitor (IκB), and imbalance of NF-κB and IκB has been associated with development of many diseases, including tumours. In this review, we focus on polymorphisms of the NFKB and NFKBI genes in relation to development of common inflammatory diseases including ulcerative colitis (UC), Crohn's disease (CD), rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, giant cell arthritis, type 1 diabetes, multiple sclerosis, celiac disease, and Parkinson's disease, as well as susceptibility of several cancers, such as oral squamous cell carcinoma, colorectal cancer (CRC), hepatocellular carcinoma, breast cancer and myeloma.

Abstract [en]

Polymorphisms of GSTM1, GSTT1 and GSTP1 were examined in melanoma patients and tumor-free individuals. Relationships between the polymorphisms and tumor characteristics and pigment phenotypes of the patients were analyzed. There was no significant difference in GSTM1 null and GSTT1 null genotypes nor GSTP1 GG genotype between melanoma patients and controls. In melanoma patients, these polymorphisms were not correlated with early or later onset of melanomas or gender of the patients. Frequency of GSTM1 null genotype was higher in patients with melanoma >2.5 mm than in those with tumors <1.0 mm, and higher frequency was found in nodular melanoma than in the other tumor types. GSTP1 GG genotype was more often found in the patients with brown and mixed eye color or brown and black hair than those with blue and green eyes or blond hair. It is unlikely that polymorphisms of GSTM1, GSTT1 and GSTP1 are general risk factors for melanoma in the Swedish population. GSTM1 null genotype was correlated with Breslow thickness and tumor type, which might serve as an additional biomarker for a rapid tumor progression. GSTP1 GG increases risk for melanoma in the subgroup of individuals with dark eyes or hair.